The Snatch is the world's fastest lift. In addition to moving the weight quickly, the snatch also moves the weight a long distance - from the ground all the way overhead. The snatch not only trains power, but is an excellent developer of balance, flexibility, coordination, speed and strength.
Again Faster produced some great videos that break down the movement for you:
Snatch Set-up - Grip
There are two different methods for determining where your hands should be on the barbell.
One is to adjust the grip until the bar hanging at arms' length rests in the crease of the hips. To check this placement, lift a knee - if the bar moves up, the grip is too narrow. (see illustration below to the right)
The other is to bring your upper arms parallel to the ground with your forearms hanging straight down. Have someone hand you the bar. Where your hands take the bar from this position is a good indicator of your snatch grip. (see illustration below to the left)
The snatch also employs the "hook" grip. This grip holds your thumb underneath your fingers instead of on top. It can be a little uncomfortable at first, but is essential for snatching heavy weights.
Snatch Set-up - Feet/Body
Besides the grip, the set-up for the snatch is very similar to the deadlift.
Snatch - Pull
Doing a full snatch is very difficult. Thankfully there are numerous progressions to get you there. It is a complex movement, but when broken down into parts, can be learned by even the most uncoordinated. Take a look at the above videos to find progressions for learning the snatch.
Snatch - Recovery (i.e Standing up)
To stay balanced, the bar must remain over the middle of the foot throughout the snatch recovery. Drive off you heels and keep your core super tight. This is one of the greatest (and most difficult) core exercises there is!
See the snatch in action in the following videos:
Check out this video of team snatches - a workout that combines skill transfer exercises with the three position snatch!
For a variation on the barbell snatch, try the one-armed dumbbell snatch:
Dumbell Snatch tri-panel, from CrossFit:[wmv]